Redis stampede on a three-locale list
After a deploy, twenty PHP workers rebuilt the same notes list three times. Redis filled up, then started evicting the keys that had just been written.
Notes
Notes on solutions, code, and trade-offs. Written while the problem is still fresh.
Memcached slabs and SSR pages of uneven size
The Vue SSR process cached full HTML in Memcached. Large article pages locked RAM into fat slabs. Small tile fragments had nowhere to live, so the hit rate fell while RSS stayed high.
InnoDB buffer pool versus JSON bodies in three languages
List endpoints selected the whole notes row. The body column is JSON with English, Russian, and German HTML. The buffer pool filled with text the grid never rendered.
nginx cache that must not see a logged-in page
A 10 second HTML microcache in shared memory is cheap. It is also wrong the moment auth_token is on the request. Bypass on the cookie, not on a guess.
Hydration that breaks on the locale, not on the markup
The server rendered Russian from the URL. The first client pass read navigator.language. Vue threw the tree. The page still worked, so the bug hid until the header jumped.
The token never belongs in JavaScript
Sanctum writes auth_token as httpOnly. The login JSON has no token field. If the page can read the session, XSS can send it away.
A feature that fits in one folder
LaraBoom keeps the resource, its fields, and the Service next to each other. Host routes and app/Http are the folders I do not create.
Redis queue that must survive a second run
The worker can die after the provider call and before the commit. Redis will deliver the job again. The second run has to be empty.
php-fpm RSS that Laravel will not show you
memory_get_usage() went back down at the end of the request. The host still grew. Copy-on-write turned shared OPcache pages into private RSS after Eloquent hydrate.
PostgreSQL JSONB is not a listing index
A GIN on payload looks complete. WHERE title->>'ru' still seq-scans. Containment and extract are different jobs.
Symfony Messenger ack is not a payment fence
Redis transport redelivers after a crash. Horizon has the same rule. Ack after the provider call is how you charge twice.
Kubernetes liveness is not a Docker healthcheck
Compose waits until php-fpm listens. Kubelet kills a pod that is still compiling OPcache. Readiness and liveness are different knobs.
React admin must not ride Vue SSR
The public site is Vue SSR. The CMS is often React. One webpack graph ships both. TTI on the catalog pays for the editor.
NestJS BFF must forward the Sanctum cookie
Laravel owns /api/login and the httpOnly auth_token. Nest maps DTOs. A second JWT in memory is a second identity.